The fix maybe easy. First adjust your mic(s) to a different position. These are very sensitive instruments and will pickup any noise at all. You may need to face them up, down, over, under or somewhere else. Trial and effort is the game.
Secondly reroute the leads in your scoot. Sometimes this doesn't take a lot, just a movement of 2 in or so, other times you need to go from one side of the bike to the other. When you do this have the bike running, headsets on with the noise present, then start moving things around. If this don't get you anywhere try some filters.